Facilitative and disruptive effects of prior exposure to shock on subsequent avoidance performance.

Acquisition of two-way avoidance by mice was slower with a light CS than with a buzzer CS, with punishment of intertrial responses than without punishment, and with a short CS-CS interval than with a long CS-CS interval (30 vs. 60 sec). Light-cued avoidance was little affected by shock level (.35-1.5 mA), whereas mice trained with the buzzer CS learned faster at 1.5 mA. Animals required to move away from light or toward light showed comparable rates of acquisition. Other CS, US, and apparatus variables (directionality of cue, maximal shock duration, and presence vs. absence of a central partition in the shuttlebox) interacted in a complex fashion with those already mentioned. This resulted in widely differing performances in what may superficially appear to be different versions of the same task. The differences in mouse and rat responses to some of the variables can contribute to an understanding of the interactions between organismic and test factors and the relative explanatory value of alternative avoidance models.

Section: Experiments La-iementioning

confidence: 99%

Bidirectional avoidance by mice as a function of CS, US, and apparatus variables

Bignami

Alleva

Amorico

et al. 1985

“…movement ratings were recorded during intershock intervals. The rating procedure was modified from Anisman and Waller (1972) and essentially consisted of recording behavior on a 5-sec time sampling basis. Movement was rated on a 4-point scale as described by Anisman and Waller (1971).…”

Section: Apparatusmentioning

confidence: 99%

“…Marquis, & Suboski, 1969). Several investigators (e.g., Anisman, 1972;Anisman & Waller. 1971;Barrett.…”

mentioning

confidence: 99%

Footshock-produced excitation and inhibition of activity in rats

Anisman

Waller

1973

Self Cite

Hooded rats received five l-sec shock presentations of 0.3. 0.5. or 1.0 rnA. Activity measures recorded during each 30-sec intershock interval and at various retention intervals (.10.2.5. and 24 h) following footshock (FS) indicated that (a) 5 sec after FS activity is directly related to shock intensity, while 10-30 sec following FS activity is inversely related to shock intensity; (b) the rate of decline in activity following FS increases with successive shock presentations; (c) activity is greater .10 h after FS than at a 2.5-or 24-h retention interval; and finally (d) shock compartment confinement increased activity and resulted in a substantial alteration in the form of retention curve in the 0.3-mA group but had lesser effects upon the retention curves of the 0.5-and 1.0-mA groups. The data were interpreted as supporting the hypothesis that the "incubation effect" is a result of a decline of the activating effects of FS.It has been demonstrated that. at an intermediate retention interval, passive avoidance performance is superior to that demonstrated at a brief or long retention interval (Zammit-Montebello, Black. Marquis, & Suboski, 1969). Several investigators (e.g., Anisman, 1972;Anisman & Waller. 1971;Barrett. Leith, & Ray, 1971) have ascribed these changes in avoidance performance to nonassociative changes in activity over time following shock. Specifically, it is assumed that footshock (FS) has a dual effect upon activity which need not be dependent on changes in fear level. That is, in addition to an inhibitory effect. FS also produces a short-lived excitation which can last as long as 10 min (Pinel. Corcoran. & Malsbury, 1971). Accordingly, activity levels may be a function of the interaction between the transient activating effects and the longer-lasting inhibitory effects of FS.Given these earlier findings. one purpose of the present investigation was to determine whether (a) the FS-produced excitation is greater following high than low shock intensities; (b) the decline in FS-produced excitation. and the extent of the FS-produced immobility. is affected by shock intensity; and (c) the FS-produced activation and its subsequent decline are affected by repeated shock presentations. The present investigation was further designed to determine whether activity is lower at an intermediate than at either a brief or long retention interval and whether increases in the strength of the immobility response produced by high shock intensities (Blanchard & Blanchard. \970) or decreases in the strength of the immobility response through shock compartment confinement (Baum. 1970) alter the form of the nonmonotonic changes in activity seen at various intervals after shock. *The research and preparation of this paper were supported by Grant AO-316 from the National Research Council of Canada to the second author. Requests for reprints should be addressed to Hymie Anisman. Department of Psychology. University of Waterloo. Waterloo. Ontario. Canada. 93 METHOD SubjectsThe Ss were 180 experimentally naive male hooded...

“…However, when an avoidance response does not remove the subject from situational stimuli which have been paired with shock, as in signaled two-way or barpress avoidance tasks, performance has been found to be related inversely to shock intensity, at least within the range of intensities usually employed. This latter finding is, in fact, one of the most reliable in the avoidance learning literature (e.g., Anisman & Waller, 1972;Bauer, 1972;Cicala & Kremer, 1969;D' Amato & Fazzaro, 1966;Freedman, Hennessy, & Groner, 1974;Kurtz & Shafer, 1967;Levine, 1966;McAllister, McAllister, & Dieter, 1976;McAllister, McAllister, & Douglass, 1971;Moyer & Korn, 1964;Theios, Lynch, & Lowe, 1966).…”

mentioning

confidence: 95%

Preexposure to situational cues produces a direct relationship between two-way avoidance learning and shock intensity

McAllister

Dieter

et al. 1979

In Experiment I, four groups of subjects (n = 16 each) were exposed to the situational stimuli of a shuttlebox apparatus for 4 h. Subsequently, 200 two-way avoidance trials were administered (100/day) with either .3-or 1.6-mA shock and with either small or large reward (presence or absence of visual stimuli following the response). Avoidance performance was directly related to shock intensity on both days and to magnitude of reward on the 2nd day. In Experiment 2, four groups of subjects (n = 24 each) were given 4 h of exposure either to the situational stimuli of the shuttlebox or to a neutral box. Then, 10 two-way avoidance trials were given with 1.6-mA shock. Subsequently, subjects were allowed to escape from one of the shuttlebox compartments to an adjacent safe box. Following preexposure to situational stimuli, avoidance performance was superior whereas escape-from-fear performance was inferior. This latter finding demonstrated that less fear of situational cues was present during avoidance training in the preexposed condition. All of these results support the effective reinforcement theory, an extension of two-factor theory, which emphasizes the importance for avoidance learning of the amount of fear of situational cues present following a response. 165In a one-way task in which subjects can avoid shock by moving to an area distinctively different from the one where shock is administered, avoidance performance has been found to be directly related to shock intensity (Dieter, 1976;Moyer & Korn, 1966). However, when an avoidance response does not remove the subject from situational stimuli which have been paired with shock, as in signaled two-way or barpress avoidance tasks, performance has been found to be related inversely to shock intensity, at least within the range of intensities usually employed. This latter finding is, in fact, one of the most reliable in the avoidance learning literature (e. A theoretical position which seems to account for the above findings is the effective reinforcement theory proposed by McAllister et al. (1971McAllister et al. ( , 1976 as an extension of the two-factor theory of avoidance learning (Mowrer, 1947). According to this position, the effective reinforcement for an avoidance response is related (a) positively to the amount of fear reduction occurring with the response and (b) negatively to the amount of fear present following the response. In addition, as the total amount of fear increases, it is assumed that the amount of fear present following the response (b) becomes relatively more important than the amount of fear reduction (a) in determining effective reinforcement. In the signaled twoway avoidance task, fear becomes conditioned to both the discrete conditioned stimulus (CS) and to the situational cues of each shuttle compartment when shock occurs on escape trials, with more fear being conditioned to these stimuli the more intense the shock. Although the amount of fear reduction would be greater in a strong-than in a weak-shock group when the CS is terminated fo...